Hybrid integrated circuits (HICs) are microelectronic devices which combine several electronic functions on a single substrate and which are relatively large in comparison to integrated circuits (ICs). To protect and prolong the reliability of microelectronic devices, they are often encapsulated (packaged) in a suitable plastic material, such as epoxy. The encapsulation is conducted so as to produce molded packages which are uniform in size and are easy to handle. The main interest lies primarily in small size packages with a large number of peripheral contacts (e.g. in quad form) and in the protection afforded the device by the encapsulating plastic material. Outside dimensions of the molded HIC packages correspond to the sizes standardized by Joint Electron Device Engineering Council (JEDEC); therefore the molded HICs may be used in spaces typically provided for ICs.
Typically, HIC's were packaged utilizing a mounting pad-and-lead frame. A schematic representation of one of such prior art encapsulated HIC package, denominated 1, is shown in crossection in FIG. 8 wherein a carrier substrate 2, such as a ceramic substrate or a printed wiring board, with a plurality of various electronic elements commonly identified as 3, such as resistors, capacitors, transistors, ICs and other elements of a HIC, was mounted on a lead frame comprising a mounting pad 4 and a plurality of leads 5. After wiring connections 6 were made to various devices, pads on the substrate and the leads of the lead frame, the entire assembly was encapsulated in a suitable plastic material, 7, such as epoxy. One variant of such prior art HIC package is disclosed in an article by T. Sasamota, N. Senba, Ohnishi and A. Sato, entitled "A New Type Hybrid IC in a Transfer-molded Standard Package", published in Proc. IEEE Int. Electronic Manufacturing Technology Symp., 1987, pp. 16-21. Unfortunately this type of design leads to thermal stresses during and post molding of the package which may affect the integrity of the wire connections 6 to leads 5, as well as of the molded package. Therefore, it is desirable to provide a molded HIC-design which would eliminate or at least reduce the possibility.